Mineral nutrient status, some quality and morphological characteristics changes in peanut (Arachis hypogaea L.) cultivars under salt stress

Abstract

Peanut (Arachis hypogaea L.) is considered to be one of the most important crops which thrive in newly reclaimed sandy soils as a leguminous crop of high nutritive value and a source of edible oil. Our study tested the effects of different salt levels on mineral nutrient partitioning (Na⁺, K⁺, Mg²⁺, Ca²⁺, P and N) and some quality (dry weight and leaf relative water content) and morphological (plant height, number of leaves) characteristics of peanut commercial cultivars. Four peanut cultivars (Mbiah, Ngondo, Pyrieur and Vanda) were used in this experiment. Three concentrations of salt solution including 50, 100 and 200 mM NaCl and the control (Wacquant nutrient solution) were used in irrigation. The pot experiment was arranged in completely randomized design with four replicates. The leaf relative water content (LRWC) provoked by the salinity in nutrient solution decreased from 85.08 to 83.43%, 87.82 to 85.30%, 85.81 to 78.20% and 85.90 to 79.70% in Mbiah, Ngondo, Pyrieur and Vanda cultivars respectively. The results showed that the salt stress reduced significantly (p<0.05) the plant height in Pyrieur cultivar from 40.49 to 21.45 cm, the number of leaves from 11.2 to 7.0, the dry weight of roots from 0.15 to 0.11 g Plant^-1, the dry weight of stems from 0.37 to 0.15 g Plant^-1 and the dry weight of leaves from 0.46 to 0.19 g Plant^-1. Similar results were obtained in Vanda cultivar where the supply of nutrient solution with salinity reduced significantly (p<0.05) the plant height from 38.26 to 26.30 cm, the number of leaves from 12.5 to 7.5, the dry weight of roots from 0.14 to 0.03 g Plant^-1, the dry weight of stems from 0.36 to 0.12 g Plant^-1 and the dry weight oh leaves from 0.46 to 0.19 g Plant^-1. The results also revealed that K⁺, Mg²⁺, Ca²⁺, P, N, K⁺/Na⁺ and Ca²⁺/Na⁺ uptake of peanut plant organs were significantly (p<0.05) reduced with increasing salinity in Pyrieur, Vanda and Mbiah except for total N accumulation in plant organs of Mbiah. The plant height, the number of leaves, the dry weight and the mineral nutrient uptake were not significantly (p>0.05) reduced under salt stress in Ngondo plant organs except at high salt-treated (200 mM NaCl). The Ngondo cultivar was observed to have relatively higher tolerance on average of all growth parameters and mineral nutrient status than others. This finding suggested that the Ngondo cultivar could be used to highlight the newly salt cultivated sandy soils in arid, semi-arid regions and similar environments across Cameroon.

Key words: Arachis hypogaea, growth parameters, mineral nutrient, plant organs, salt stress.